Drawn branched filament



Get. 18, 1965' sc c; ETAL 3,280,241

DRAWN BRANCHED FILAMENT Filed Sept. 6, 1962 FIG. 2.-

-FIG. 3.-

INVENTOR:

United States Patent Ofifice 3,Z8fi',24l Patented Oct. 18, 19563,280,241 DRAWN BRANCHED FILAMENT Frederick Scragg and Alexander AlbertChnbb, Macclesfield, England, assignors to Ernest Scragg & Sons Limited,Macclesfield, England Filed Sept. 6, 1962, Ser. No. 222,993 Claimspriority, application Great Britain, Dec. 6, 1960, 41,955/60; Sept. 6,1961, 32,008/61 6 Claims. (Cl. 264-290) This application is acontinuation-in-part of co-pending application Serial No. 157,080, filedDecember 5, 1961, now US. Pat. No. 3,243,339, and entitled Yarn andProcess and Apparatus for Manufacturing the Same.

The present invention relates to branched textile filaments and aprocess used during the manufacture of such filaments.

As is disclosed in the above application it is possible to manufacturethermoplastic yarns which have branches from the filamentary portions ofthe yarns. The filament is produced from synthetic thermoplasticmaterial having a highly polymerized molecular structure, and thefilament is distinguished by having a series of side projections orbranches which are produced in a manner described in the aboveapplication. It is known that in order to provide a filament with astructure enabling it to be used as a textile yarn it must be drawn soas to orient its molecular structure and increase its strength.

It is accordingly a primary object of the present invention to provide abranched filament of the above type which has both the filamentaryportion thereof as well as the branches which project .therefromoriented with respect to their molecular structure and of an increasedstrength as compared to the untreated yarn, and the objects of thepresent invention also include the process for manufacturing this yarn.

It is in particular an object of the present invention to provide aprocess during which the branched filament will be drawn not only at itselongated filamentary portion from which the branches project but alsoat the branches themselves, so that in this way as a result of thedrawing, the drawn yarn has at its filamentary portion a lesser diameterthan the diameter of the untreated yarn and also the branches are of asmaller diameter than the branches of the undrawn yarn, and in this waythe rigidity of both the filamentary portion of the yarn as well as thebranches thereof is increased.

Also, the objects of the present invention include a process wherein thefilament is initially placed in a condition which will promote theproper drawing thereof both at its branches and at its filamentaryportion, as well as a process which after the drawing of the yarn willrestore it to the condition where the branches project from thefilamentary portion of the yarn. With these objects in view theinvention includes, in a process for manufacturing a branchedthermoplastic filament, the steps of bending the branches of thethermoplastic filament inwardly toward the filamentary port-ion thereofon which the branches project, and then drawing the filament both at itsfilamentary portion as well as at its branches, preferably with thesimultaneous application of heat to the filament, so that in this waythe filament is drawn both at its filamentary portion and at itsbranches to improve its molecular structure as well as to increase itsstrength.

After drawing of the filamentary portion and the branches, the latterare preferably brushed up from the filamentary portion. Also, the yarncan be treated in accordance with the invention either separately orpreferably in relatively large numbers of filaments which are treatedsimultaneously, the filaments being combined as,

The novel features which are considered as characteristic for theinvention are set forth in particular in the appended claims. Theinvention itself, however, both as to its construction and its method ofoperation together with additional objects and advantages thereof, willbe best understood from the following description of specificembodiments when read in connection with the accompanying drawings, inwhich:

FIG. 1 is a schematic side elevation of one embodiment of an apparatuswhich may be used to practice the process of the invention in order tomanufacture the yarn of the invention;

FIG. 2 is a side elevation of an embodiment similar to FIG. 1 butincluding more detail with respect to the particular components;

FIG. 3 is a schematic illustration of an untreated filament before ithas been drawn according to the invention;

FIG. 4 is a schematic illustration of the filament of FIG. 3 after ithas been drawn; and

FIG. 5 shows a schematic plan view of the manner in which the drawingrolls act on the filament, the line along which the drawing rolls engagethe filament being shown in a dot-dash line in FIG. 5

Referring now to FIG. 1, there is shown therein a roll 11 of untreatedfilament 12, this filament passing through a known condenser 26 so as tohave the branches bent inwardly toward the axis of the filament alongwhich the filamentary portion thereof extends, the branches projectingfrom the filamentary portion. Thus, with the filament 12 moving to theright, as viewed in FIG. 1, the free ends of the branches will bedirected toward the left, as viewed in FlG. 1, and a first pair ofdrawing rolls 13 and 14 receive the filament 12 from the condenser, oneor both of the rolls 13 and 14 being heated so that the filament will beheated.

The filament is received from the first pair of drawing rolls 13, 14 bya second pair of drawing rolls 15, 16 which rotate at a speed fasterthan the rolls 13, 1 4 so that the filament is drawn as it passes alongthe path extending between the pairs of drawing rolls.

The structure is shown in FIG. 2 where the filament moves to the right,the supply roll 11 being shown at the left, and as is indicated in FIG.2 before the filament reaches the drawing rolls 13, 14 it passes betweena pair of rolls 17, 18 which absorb any tension differences experiencedduring unwinding of the untreated filament 12 from the roll 11 and whichprovide a uniform rate of feed of the filament to the first pair ofdrawing rolls 13, 14. The rolls 14 and 18 are driven from a common motor19 through an endless belt 20 which engages pulleys driven by the motoras well as coaxial with the rolls 14 and 18 connected thereto, and aheating means is shown diagrammatically in FIG. 2 connected operativelywith the lower roller 14 of the first pair of drafting rolls 13, 14. Forexample, the roll 14 may be hollow and may have in its interior anelectrical heating element 25 connected electrically with slip ringslocated at an end wall, or at both end walls, of the roll 14 andengaging brushes which are connected electrically to a source of currentwhich places the heating elements in the interior of the roll in anelectrical circuit which will cause them to become heated and to heatthe roll :14 so that in this way the yarn itself will be heated as itpasses between the rolls 13, 14.

In order to insure that the filament is securely gripped between thesecond pair of rolls 15, 16 a circumferentially grooved idler roll 21permits the filament to be wrapped twice around the roll 15, thefilament passing around the idler 21, before passing around a guidemember 22 so as to be finally collected on the package 23 which takes upthe filament in a known manner by frictionally engaging, through its ownweight, the peripheral surface of a driving roll 24, as indicated inFIG. 2.

The filament 12 is indicated in FIG. 3 before it is treated according tothe invention and as may be seen the branches of the filament extend insuch a direction that when the filament is between the rolls 13, 14 and15, 16, the free ends of the branches of the filament are directedtoward the rolls 13, 14. As may be seen from FIG. 5, the rolls 13, 14grip the filament as it moves to the right, as viewed in FIG. 5, alongthe dot-dash line indicated in FIG. 5 with the diameter of thefilamentary portion as Well as the branch becoming smaller as shown onan exaggerated scale in FIG. 5, as the yarn advances to the right, asviewed in FIG. 5, beyond the line where the yarn is gripped between therolls 13, 14. Of course, it is the faster speed of the rolls 15, 16which draws the yarn so that it will become elongated at the line alongwhich it is gripped by the first pair of drawing rolls, as indicated inFIG. 5.

The resulting filament according to the invention is illustrated in FIG.4 which, as compared with FIG. 3 clearly indicates how the filament hashad its diameter reduced both along its filamentary portion as well asalong the branches extending from the filamentary portions, and it willbe noted from a comparison of FIGS. 3 and 4, how much longer thebranches are in FIG. 4 than in FIG. 3. Any suitable rotary brushes orthe like may be applied to the filament in order to brush up thebranches thereof subsequent to the drawing operation.

The bending of the branches by the condenser bends inwardly toward thefilamentary portion of the filament so that the branches shown in FIG. 3will turn in a substantially counterclockwise direction with respect tothe junctions between these branches and the filamentary portion of thefilament during the inward bending of the branches by the condenser. Asis apparent from the above description, the yarn of the inventionmanufactured according to the process of the invention can becontinuously treated so as to produce a branched filamentary structureto be used in connection with textile materials wherein the filamentsare fully drawn so that the maximum strength of the material is achievedboth.

in the filamentary portion thereof as well as in its branches, and thematerial may be dyed either before or after the drawing operations, orthe dye may be incorporated in the melt from which the filaments areformed.

It will be understood that each of the elements described above or twoor more together, may also find a useful application in other types. oftextiles differing from the types described above.

While the invention has been illustrated and described as embodied inthermoplastic filaments, it is not intended to be limited to the detailsshown, since various modifications and structural changes may be madewithout departing in any way from the spirit of the present invention.

Without further analysis the foregoing will so fully reveal the gist ofthe present invention that others can by applying current knowledgereadily adapt it for various applications without omitting featuresthat, from the standpoint of prior art, fairly constitute essentialcharacteristics of the generic or specific aspects of this inventionand, therefore, such adaptations should and are intended to becomprehended within the meaning and range of equivalence of thefollowing claims.

Thus, it is not necessary to use a condenser if the filament is made ina particular manner. If the branches are produced in such a manner as toproject substantially at right angles to the line of the filament, thensome bending device is of course necessary. However, it is just as easyto cast or extrude a shape in which the branches lie substantiallyparallel with the main filament at an angle substantially as shown inFIGS. 4 and 5, in which case the condenser is unnecessary.

What is claimed and desired to be secured by Letters Patent is:

1. In a process for manufacturing from thermoplastic material a branchedtextile filament comprising a trunk and a plurality of branches each ofwhich extends substantially lengthwise of the trunk and is connected tosaid trunk at an end thereof, the step of engaging and pulling the trunkand free ends of the branches of said filaments so that portions of saidbranches spaced from said connected ends as well as said trunk arestretched, whereby the molecular orientation of the trunk as well as ofsaid branches will be improved.

2. A process as defined in claim 1, and further comprising the initialstep of bending said branches inwardly toward said trunk from which theyproject.

3. A process as defined in claim 1, and further comprising the step ofheating the filament simultaneously with the pulling of said trunk andbranches.

4. A process as defined in claim 1, and further comprising the step ofbrushing up the branches from said trunk of the filament subsequent topulling of said trunk and branches.

5. A process as defined in claim 2, wherein the step of bending saidbranches inwardly includes directing the filament through a condenser.

6. A process as defined in claim 1, wherein the step of stretching saidtrunk and said branches includes directing the filament along a pathextending between two pairs of drawing rolls, one pair of which rotatesat a speed which is faster than the speed of the other.

References Cited by the Examiner UNITED STATES PATENTS l,881,337 10/1932Willis 264l62 2,012,984 9/1935 Bradshaw 18-8 2,347,036 4/ 1944 Durnont264-290 2,394,540 2/1946 Finzel 264290 2,423,182 7/1947 Fields 2642902,778,058 1/ 1957 Gabler 18-8 3,127,915 4/ 1964 Bottomley.

ALEXANDER I-I. BRODMERKEL, Primary Examiner.

A. L. LEAVITT, F. S. WHISENHUNT,

Assistant Examiners.

1. IN A PROCESS FOR MANUFACTURING FROM THERMOPLASTIC MATERIAL A BRANCHEDTEXTILE FILAMENT COMPRISING A TRUNK AND A PLURALITY OF BRANCHES EACH OFWHICH EXTENDS SUBSTANTIALLY LENGTHWISE OF THE TRUNK AND IS CONNECTED TOSAID TRUNK AT AN END THEREOF, THE STEP OF ENGAGING AND PULLING THE TRUNKAND FREE ENDS OF THE BRANCHES OF SAID FILAMENTS SO THAT PORTIONS OF SAIDBRANCHES SPACED FROM SAID CONNECTED ENDS AS WELL AS SAID TRUNK ARESTRETCHED, WHEREBY THE MOLECULAR ORIENTATION OF THE TRUNK AS WELL AS OFSAID BRANCHES WILL BE IMPROVED.